Why do Atheists try to sound literate or smart when asked about god?

I see so many questions asked about if God exists, and they tend to give theoretical or scientific answers along with bashing the existence as far as they can. If you need clues about his existence, if all matter just appeared one day..how could that happen? What matter would be there to appear? Could something come from nothing? Isn't it obvious that a higher being had to create? They say it all just appeared. If that's believable then why isn't the existence of God believable? Because in the past you or scientists couldn't do what it says in the Bible? The miracles performed? How could all of this be done without a being? Once you think about it, our bodies and all other bodies are so sophisticated that it couldn't occur naturally I mean come on. The ocean, the sky, storms, art, anything here on earth and anywhere in the universe. Do you really believe it could just appear at this level? Science can't figure out everything, no way no how. God created everything NOT man. And man did not create God. Such a significant thing such as the Bible wasn't created by just one man. So how could God be created by man?